Arched protective inner sole



Aug. 27, 1957 L. P. FRIEDER ET AL 2,803,895

' ARCHED PROTECTIVE INNER SOLE Filed, May 26, 1955 INVENTORS LEOA/HRD R FJQ/EDER Wm 5. F/NKEN A ORNEY ARCHED PROTECTIVE INNER SOLE Leonard P. Frieder, Great Neck, and Walter S. Finlren, Brooklyn, N. Y., assignors to General Textile Mills, Inc., New York, N. Y., a corporation of Delaware Application May 26, 1955, Serial No. 511,290

4 Claims. (Cl. 36--71) Our invention relates to an arched protective inner sole and more particularly to an arched protective inner sole for a safety shoe for preventing injury to the foot of a wearer from sharp objects penetrating the safety shoe sole.

In our copending application Serial No. 487,269, filed February 10, 1955, we disclose an inner sole for protecting the wearers foot against injury from sharpobjects penetrating the sole of the safety shoe, or the like, with which the protective inner sole is used. The protective inner sole shown in the copending application includes a plurality of flat, stacked, resin-impregnated, fibrous laminates bonded over a limited area to permit differential deflection of the respective laminates in resisting penetration by sharp objects. We have discovered that we may improve on the penetration resisting properties of this inner sole by forming a more resilient sole. We form our arched inner sole to the contour of a foot so as to be more comfortable and more healthful than the flat inner sole disclosed in our copending application.

One object of our invention is to provide an arched protective inner sole for a safety shoe, or the like, for preventing injury to the wearers foot by sharp objects penetrating the shoe sole.

A further object of our invention is to provide an arched protective inner sole which is comfortable and healthful.

Other and further objects of our invention will appear from the following description.

In general, our invention contemplates the provision of an arched protective inner sole including a plurality of stacked laminates having, along a major portion of the major axis of the sole, arcuate cross sections of progressively increasing radius from the top laminate to the bottom laminate. We form our laminates of synthetic resin-impregnated, fibrous material and bond the laminates to each other over a limited area to permit the laminates to deflect with respect to each other. We conform our inner sole to the contour of the sole of a foot to provide a comfortable and healthful safety inner sole.

In the accompanying drawings which form part of the instant specification and which are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:

Figure 1 is a plan View of one form of our arched protective inner sole.

Figure 2 is a sectional view of our arched protective inner sole, taken along the line 2-2 of Figure 1.

Figure 3 is a sectional view, drawn on an enlarged scale, of our arched protective inner sole, taken along the line 33 of Figure 1.

Figure 4 is a sectional view, drawn on an enlarged scale, of our arched protective inner sole, taken along the line 4-4 of Figure 1.

Figure 5 is a plan view of an alternate form of our arched protective inner sole.

More particularly referring now to the drawings, our

2,393,895 Patented Aug. 27, 1957 arched protective inner sole, indicated generally by the reference character 10, includes a plurality of stacked, fibrous, resin-impregnated laminates 12, 14, and 16. While we have shown our inner sole as including only three laminates 12, 14, and 16, it will readily be understood that we may employ as many laminates as are necessary to afford the degree of protection required. The laminates 12, 14, and 16 may be formed of any suitable matted, felted, woven, knitted, or braided fibrous material. Preferably, we employ spun glass fibers, but we may use any other plastic material such as nylon, or the like. We impregnate the fibrous laminates with a thermoplastic or thermosetting resinous material, such, for example, as polyethylene plastic, allyl plastic, polystyrene plastic, phenol formaldehyde, or urea formaldehyde resins. Preferably we use a polyester resin.

As can be seen by reference to Figure 2, we form each of the laminates 12, 14, and 16 with an arcuate cross sec-' tion along a major protion of the major axis of the laminate. Laminates 12, 14, and 16 have radii R1, R2, and R3 which increase progressively from radius R1 of the top laminate 12 to radius R3 of the bottom laminate 16. This construction results in voids 18 and 20 between respective adjacent pairs of laminates 12 and 14 and 14 and 16. It will be appreciated that this construction provides a protective inner sole having substantially greater resilience than the protective inner sole disclosed in our said copending application. A sharp object impinging on the undersurface of the bottom laminate 16 deflects it through the void 20 before laminate 16 comes in contact with the intermediate laminate 14. Laminates 14 and 16 are then deflected through the void 18 before laminate 14 comes in contact with the top laminate 12 on which the wearers foot rests. This increased deflection greatly increases the penetration resisting qualities of the inner sole.

For an inner sole having a curved cross section having a chord length L, the radii of the laminates 12, 14, and 16 may readily he arrived at by use of a simple formula. If x is the desired distance along a radius of the arcuate cross section of the laminate between the plane on which the inner sole 1t) rests and the upper surface of the laminate, that is, the rise of the major or longitudinal arch, the radius R of the longitudinal arch of the particular laminate may be determined from the formula:

From Equation 1 the radius of any laminate longitudinal arch of a stack may easily be determined.

In order to retain the laminates of our inner sole in stacked relation, we bond the laminates to each other in the area of the toe 22 or heel 24 of the inner sole. As is shown in Figure 1, this bonding may expeditiously be accomplished by stitching 26 passing through the heel of the inner sole. Alternately, as is shown in Figure 5, bonding may be accomplished by fusing the resin-impregnating material of the respective laminates in a limited area 28 of the toe of the sole. It will be understood that a bonded area could replace stitching 26 in the heel portion of the sole or stitching could replace the bonded area 28 in the toe of the sole.

In order to provide a more comfortable and healthful Sole, we have conformed our inner sole generally to the contour of the sole of a foot. We provide our sole with a transverse or minor arch, indicated generally by the reference character 30, for supporting the inboard portion of the minor or transverse arch of the foot. We accomplish this by making each of the laminates with an upwardly curving portion 32 in the area underlying the inboard portion of the transverse arch of the wearers foot. .The radius of curvature of each of the portions32 increases from thepoint on the sole underlying the shoe welt to a point of maximum radius and then decreases to zero at the beginning of the heel of the inner sole. This varying radius .of curvature is illustrated in Figures '3 and 4. The heel. portion .24 .of our arched'inner sole curves slightly upwardly to theedge of .thesole further to shape the sole to the wearers foot.

-While we have shown the curved laminates 12, .114, and 16 of our sole as forming voids 18 andt20 between adjacent pairs of laminates, it-is tobe understood that we may fill the voids with a-suitableelastic or resilient materialsuch :as sponge rubber orthe'like to afford/additional: resistance to deflection of the laminates.

.In use, our protectivelinner solernay besinserte'ddnta safety shoe,.or thelike with which it is to be used. Alternately it may be disposed betweenthe insole and outsole of a. safetyshoesso as to form part of-a safety shoe during the rm'anufacture ofthe shoe. Whena-sharp object impinges on the undersurface 'of the: bottom Llaminate 16 of the'innensole, it deflects laminate -16 through-the void -20 between laminates .16 ar1d 14. It thendeflects laminates 16 and 1 4 togetherthrough the voidf-18'before laminatef1'4 .comes in contact with the laminate 1-2-on which the wearers foot rests. This deflection of the stacked laminates through the distance of the voids 18 and 20Iabsorbs theforce of penetration -of the sharp objectand resistspe'netration of the inner sole. The' surface-configuration -or contour of our improved inner solesupports thewearefis foot in a healthfuLand'comfortable manner.

-It will'be seen that we have accomplished the objects of our invention. Wehave provided an arched inner sole which-is .highly:resilient so as to'aiford improved protection against penetration by sharp objects or the like impinging on the "inner sole. Our sole is healthful and comfortable.

It "willbe understood that certain features and subcombinationsare of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the'scope of our claims. It-is further obvious that various changes maybe made in details within the scope 'of our claims without departing from the spirit of ourinvention. It is therefore to be understood that our invention is not to be limited to the specific details shown and described.

Having thus described our invention, what we claim is:

1. A protective inner sole for protecting the sole of a wearers foot comprising in combination, a plurality of stacked laminates including atop laminate, a bottom laminate, each of said laminates having a pair of ends and an area substantially coextensive with the sole area of the wearers .foot and means for securingsaid'laminates in assembled relationship ata respective corresponding end of each laminate, the other ends of said laminates being free to permit relative movement between said other ends, each of said'laminates being preformed with an arcuate curvature along its longitudinal axis,-the longitudinal curvature of each of said laminates being determined by a radius, the radii of the respective laminates increasing progressively from the top laminate to the bottom laminate.

2. 'Aprotective inner sole as in claim -1-in which-each of said laminates is formed from "synthetic resin impregnated fibrous material.

3. A protective inner sole/as in claim l-in-which each of said laminates is transversely curved to provide a minor arch support.

14. A protective inner sole forprotecting the sole of a wearersfoot comprising in'combinat-ion a plurality of stacked resin impregnated fibrous laminates'including a toplaminate and a bottomlaminate, each of said laminatesuhaving an area substantially coextensive-with the solezarea ofthe wearers foot, said laminates being preformed with difierential longitudinal curvatures to provide voids between adjacentlaminates and means for retaining saidlaminates-in stacked relationship while permitting portions ofsaid laminates to slide relative to each other.

References Cited in the file of this patent UNITED STATES PATENTS $880,245 Scholl Feb. 25, 1908 881,343 Ruhmann Mar. 10, 1908 1,036,452 Childs Aug. 20, 1912 1,575,645 Scholl Mar. 9, 1926 1,671,713 Glass Apr. 6, 1927 2,653,396 Gottlieb Sept. 29, 1953 

